1. Field of the Invention
The present invention relates to an image forming apparatus such as a copying machine, facsimile apparatus, printer or the like, and more particularly to a development device used in such image forming apparatus, as well as a process cartridge using the development device.
2. Description of the Background Art
As a development device that is used in this type of image forming apparatus, there has conventionally be known a development device that has a developer supporter container, a developer container for storing the developer, a communication port communicating the developer supporter container with the developer container, and communication port sealing means for sealing the communication port. By providing the communication port sealing means in the development device, the developer can be prevented from leaking and dispersing from an opening section of the developer supporter container when carrying the development device alone. Also, since the developer is separated from the external air, deterioration of the developer that is caused when the developer contacts with the air can be prevented.
For example, Japanese Unexamined Patent Application Publication No. 2006-23619 discloses a development device that is provided with the communication port sealing means having a frame body for forming the communication port, and a seal member adhered to the frame body so as to cover the communication port. In this development device, the seal member adhered to the frame body of the communication port sealing means is peeled off when starting to use the development device, whereby the development supporter container and the developer container can be communicated with each other, and the developer can be supplied to the developer supporter container.
However, this conventional developer apparatus had to be designed such that the sheet thickness of the frame body of the communication port sealing means had to be thick in order to ensure the strength thereof for peeling off the seal member, or a bent section had to be provided on an end section of the frame body. In the case in which a PET resin (polyethylene terephthalate resin) is used as the material of the frame body, thickening the sheet thickness leads to increase of the cost. Moreover, when providing the bent section by means of a thick PET resin material, cracks and scuffing are formed on the bent section due to its hardness, causing poor mold formability. Furthermore, the seal member formed from a PET film into a two-sided tape was generally adhered to the frame body composed of the PET resin. However, when pulling out the seal member the two-sided tape that is nearly peeling off abuts on the developer supporter, whereby a developer layer on the developer supporter is sometimes damaged, or the completely peeled two-sided tape enters the developer supporter container, resulting in a defective image with white stripes and the like. Therefore, there was a problem that the use of such two-sided tape to adhere the seal member is not enough to obtain a high-quality image.
Technologies relating to the present invention are also disclosed in, e.g., Japanese Patent Application No. 3402872.